The nature of the phase transitions in La1−xCaxMnO3 and Pr0.48Ca0.52MnO3 has been probed using heat capacity and magnetisation measurements. The phase transition associated with the onset of the stripe phase has been identified as second order. The model of a Peierls transition in a disordered system (a `dirty' Peierls transition) is shown to provide an extremely good fit to this transition. In addition, an unexpected magnetic phase has been revealed in low temperature Pr0.48Ca0.52MnO3, associated with an excess heat capacity over a wide temperature range compared to La1−xCaxMnO3.
@article{arxiv.cond-mat/0610276,
title = {Dirty Peierls transition to stripe phase in manganites},
author = {S. Cox and J. C. Lashley and E. Rosten and J. Singleton and A. J. Williams and P. B. Littlewood},
journal= {arXiv preprint arXiv:cond-mat/0610276},
year = {2007}
}